Oops: divide error: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 3509 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: netns cleanup_net RIP: 0010:comedi_inc_scan_progress+0x1a4/0x430 drivers/comedi/drivers.c:563 Code: b6 0c 19 84 c9 0f 85 bd 01 00 00 03 45 2c 4c 8d a5 80 00 00 00 4c 89 e1 48 c1 e9 03 0f b6 0c 19 84 c9 0f 85 cc 01 00 00 31 d2 <41> f7 34 24 41 89 17 45 89 ec eb 0f e8 5b 6f 06 f9 48 bb 00 00 00 RSP: 0018:ffffc90000007a00 EFLAGS: 00010046 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888050110400 R08: dffffc0000000000 R09: 1ffff1100ee74400 R10: dffffc0000000000 R11: ffffed100ee74401 R12: ffff888050110480 R13: 0000000000000002 R14: 0000000000000000 R15: ffff88805011042c FS: 0000000000000000(0000) GS:ffff888125d06000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32f1bff8 CR3: 000000007726a000 CR4: 0000000000350ef0 Call Trace: comedi_buf_write_samples+0x373/0x5a0 drivers/comedi/comedi_buf.c:603 parport_interrupt+0xf3/0x150 drivers/comedi/drivers/comedi_parport.c:218 __handle_irq_event_percpu+0x295/0xab0 kernel/irq/handle.c:203 handle_irq_event_percpu kernel/irq/handle.c:240 [inline] handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:257 handle_edge_irq+0x23b/0xa10 kernel/irq/chip.c:855 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline] handle_irq arch/x86/kernel/irq.c:254 [inline] call_irq_handler arch/x86/kernel/irq.c:-1 [inline] __common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:325 common_interrupt+0x5e/0xe0 arch/x86/kernel/irq.c:318 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 RIP: 0010:variable_ffs arch/x86/include/asm/bitops.h:312 [inline] RIP: 0010:handle_softirqs+0x1b0/0x870 kernel/softirq.c:610 Code: 89 64 24 30 0f b7 db 48 c7 c7 e0 b3 69 8b e8 f7 d8 c8 09 65 66 c7 05 c5 9c 0c 11 00 00 e8 68 ff 42 00 fb 49 c7 c7 c0 c0 e0 8d ff ff ff ff 0f bc c3 41 89 c5 41 ff c5 0f 84 c2 03 00 00 89 5c RSP: 0018:ffffc90000007e40 EFLAGS: 00000286 RAX: c6b72eee4a25a500 RBX: 0000000000000004 RCX: c6b72eee4a25a500 RDX: 0000000000000002 RSI: ffffffff8d7eb243 RDI: ffffffff8bc07360 RBP: ffffc90000007f50 R08: ffffffff8f9e1577 R09: 1ffffffff1f3c2ae R10: dffffc0000000000 R11: fffffbfff1f3c2af R12: 000000000000000a R13: 0000000000000000 R14: dffffc0000000000 R15: ffffffff8de0c0c0 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__might_sleep+0x7b/0x100 kernel/sched/core.c:8856 Code: 3d 00 00 74 14 49 89 fe 48 89 df 41 89 f4 e8 6c 23 94 00 4c 89 f7 44 89 e6 48 83 3b 00 74 09 80 3d ba 4c f6 0d 00 74 11 31 d2 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 86 00 00 00 49 89 fe 41 89 f4 c6 RSP: 0018:ffffc9000c2b7468 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff88802fda9e40 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00000000000003cd RDI: ffffffff8d8cb63e RBP: 0000000000000000 R08: ffffffff8f9e1577 R09: 1ffffffff1f3c2ae R10: dffffc0000000000 R11: fffffbfff1f3c2af R12: dffffc0000000000 R13: 0000000000001000 R14: ffff88802fda9e58 R15: dffffc0000000000 synchronize_rcu_expedited+0x4c6/0x730 kernel/rcu/tree_exp.h:972 lockdep_unregister_key+0x29b/0x310 kernel/locking/lockdep.c:6628 __qdisc_destroy+0x166/0x420 net/sched/sch_generic.c:1083 qdisc_put net/sched/sch_generic.c:1109 [inline] dev_shutdown+0x34c/0x440 net/sched/sch_generic.c:1497 unregister_netdevice_many_notify+0x118c/0x2390 net/core/dev.c:12272 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline] ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:248 cleanup_net+0x4d8/0x820 net/core/net_namespace.c:695 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:comedi_inc_scan_progress+0x1a4/0x430 drivers/comedi/drivers.c:563 Code: b6 0c 19 84 c9 0f 85 bd 01 00 00 03 45 2c 4c 8d a5 80 00 00 00 4c 89 e1 48 c1 e9 03 0f b6 0c 19 84 c9 0f 85 cc 01 00 00 31 d2 <41> f7 34 24 41 89 17 45 89 ec eb 0f e8 5b 6f 06 f9 48 bb 00 00 00 RSP: 0018:ffffc90000007a00 EFLAGS: 00010046 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888050110400 R08: dffffc0000000000 R09: 1ffff1100ee74400 R10: dffffc0000000000 R11: ffffed100ee74401 R12: ffff888050110480 R13: 0000000000000002 R14: 0000000000000000 R15: ffff88805011042c FS: 0000000000000000(0000) GS:ffff888125d06000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32f1bff8 CR3: 000000007726a000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess): 0: b6 0c mov $0xc,%dh 2: 19 84 c9 0f 85 bd 01 sbb %eax,0x1bd850f(%rcx,%rcx,8) 9: 00 00 add %al,(%rax) b: 03 45 2c add 0x2c(%rbp),%eax e: 4c 8d a5 80 00 00 00 lea 0x80(%rbp),%r12 15: 4c 89 e1 mov %r12,%rcx 18: 48 c1 e9 03 shr $0x3,%rcx 1c: 0f b6 0c 19 movzbl (%rcx,%rbx,1),%ecx 20: 84 c9 test %cl,%cl 22: 0f 85 cc 01 00 00 jne 0x1f4 28: 31 d2 xor %edx,%edx * 2a: 41 f7 34 24 divl (%r12) <-- trapping instruction 2e: 41 89 17 mov %edx,(%r15) 31: 45 89 ec mov %r13d,%r12d 34: eb 0f jmp 0x45 36: e8 5b 6f 06 f9 call 0xf9066f96 3b: 48 rex.W 3c: bb .byte 0xbb 3d: 00 00 add %al,(%rax)